Learning About the Layers of the Earth

Have you ever wondered just what the Planet we live on is made from? I know I certainly did! I remember when I was younger, before learning about this in class, I thought that the Earth was just made completely of dirt! So I thought no matter how deep you dug, it would be all dirt! Basically if you were to cut open you would see four different layers that make up our Earth. These four layers are the Inner Core, Outer Core, Mantle, and Crust. Each layer has it’s own purpose and function and we are going to learn all about the layers of the Earth today! So let’s get right into it!

Crust: The Earth’s Crust is the very outer layer and the one that we live on! It consists of two different parts of the earth’s crust. These two layers are known as the continental and oceanic crusts. The Earth’s crust is made up of various types of rocks, the continental is made up of igneous rocks, and the oceanic is made up of basalt rocks. The temperature of the Earth’s crust varies from 200-400 degrees celsius. Another fun fact about the Earth’s Crust is that it is constantly moving!

Mantle: The next layer is the Mantle, which is also split into two different parts. These two parts are the lithosphere, and the asthenosphere. The lithosphere is a rock that made completely of iron and nickel, and the asthenosphere is a fluid that has a plastic-like texture. The two different layers have very different temperatures, the lithosphere is around 300 to 500 degrees, and the asthenosphere can get up to 4,500 degrees celsius! The Mantle takes up 84% of the Earth! One last fun fact about the mantle is that it actually grows bigger each year by 1 meter!

Outer Core: Getting deeper into the center of the Earth, the next layer is the Outer Core. This layer is made up of a liquefied iron and nickel. The outer core is very hot, being around 4,400 degrees celsius. This layer puts pressure on the very inner core, it is the second hottest layer, and the depth of the outer core is 2,890. A fun fact about the outer core is that it was discovered in 1936 by a seismologist named Inge Lehmann.

Inner Core: Alrighty, we made it to the last layer! The very inner layer is the Inner Core. Just like the outer core, the inner core is made up of iron and nickel, however, it is a solid layer because the other three layers are putting pressure on this layer. It is the hottest layer, being hotter than the surface of the sun! The inner core is 5505 degrees celsius! This layer was discovered in 1971!

Well, there you have it! If you are interested in studying more about the layers of the Earth with your kids or doing a unit study with them, here are some great worksheets and activities to get you started: